Method and device for cutting weft thread ends projecting from the fabric



Search Roon Nov. 27, 1945. A. MOESSINGER 2,389,809

METHOD AND DEVICE FOR CUTTING WEFT THREAD ENDS PROJECTING FROM THEFABRIC Filed March 18, 1943 2 Sheets-Sheet 1 ALQBAY'RTMOEJSINGER.

ATTORNEY.

Nov. 27, 1945.

A. MOESSINGER METHOD AND DEVICE FOR CUTTING WEFT THREAD ENDS PROJEC'IINGFROM THE FABRIC Filed March 18, 1943 2 Sheets-Sheet 2 INVENTOR. IALazkrMo SINGER.

BY/(l ATTORNEK y n-mum Patented Nov. 27, 1945 SEBTCH H METHOD AND DEVICEFOR CUTTING WEFT THREAD ENDS PROJECTING FROM THE FABRIC AlbertMoessinger, Winterthur, Switzerland, assignor to Sulzer Frres, SocitAnonyme, Winterthur, Switzerland Application March 18, 1943, Serial No.4795539 In Switzerland June 11, 1942 Claims.

When weaving on automatic looms, at each change of bobbins a, piece ofthe weft from the old bobbin and a piece from the new one will projectfrom the edge f the fabric. In multiplebox looms the various weftthreads will make loops which project from the fabric. In gripper looms,where the thread is cut off after each insertion, the weft threads alsoproject from the fabric. All these projecting weft threads diminish theselling value of the fabric. The devices hitherto known for cutting offthe ends of the weft threads are either so complicated that they havenot been introduced into weaving practice, or so imperfect that thecut-off weft thread ends still project from the edge of the fabric.Through the present invention the weft thread ends can be cut ofi withvery simple means at an exact and alway uniform distance from the edgeof the fabric.

The invention relates to a method and a device for cutting off the endsof the weft thread projecting from the fabric and consists in that theprojecting weft thread ends are bound together by binding threadsrunning in the direction of the warp, and that the projecting weftthread ends are cut off between the fabric and the outermost bindingthreads which are held in tension. The device for carrying out themethod consists in that the projecting weft thread ends are boundtogether by binding threads controlled by the loom in a known manner,that a cutting device severs these weft thread ends between the fabricand the binding threads, and that the outermost binding threads are keptin tension by a tensioning device.

The weft threads can be connected by a continuous rotation of thebinding threads (twist binding). The binding threads can change theirshed when the shuttle is at the other side of the fabric. The bindingthreads may change their shed at each pick. According to the invention apair of binding threads close to the warp threads and a second pair ofbinding threads a little further from the fabric bind the weft threadstogether, and the weft threads are cut off from the fabric between thetwo pairs of binding threads. The cutting device may be movable in thedirection of the weft threads and be pressed lightly either towards thefabric or towards the outer binding threads. The binding threads whenseparated from the fabric may be kept in tension by and wound on to abobbin driven through a friction coupling by the machine.

In Figs. 1 to 4 some examples of embodiments of the invention are showndiagrammatically.

Fig. 1 shows the fabric I with the weft thread ends 2 projecting fromit. Close to the warp threads 3 the weft threads 2 are connectedtogether by a pair f binding threads 4. A little further away from thefabric, the weft threads 2 are again connected together by a second pairof binding threads 5. Between these two pairs of binding threads 4 and 5the weft threads 2 are cut by a knife 6. The knife 6 is fixed to one armI of a double armed lever which is pivoted at a fixed point 8. A secondarm I, at right angle to the arm I, is acted on by a spring 9 which isconnected to a fixed part [0. Under the influence of this spring 9 theknife 6 is pressed close to the binding threads 4 beside the warpthreads 3. In this way the cut weft thread ends projecting from thefabric I and/or from the binding threads 4 become quite short and alwaysof the same length. Depending on the extension of the knife from thecutting-edge 2| to the side 20 pressed against the fabric, the weftthread ends, after being cut by the knife, will still project more orless from the fabric. The other pair of binding threads 5 is led overguide rods 22, 23 and rolled up on a tensioning device consisting of abobbin ll driven through a friction coupling I3, IS. The severed weftthread ends may for instance, be treated as waste or used again. A chainwheel I2 is pivotally mounted on a bolt l6 and is rotated continuouslyby the loom through the chain l4. On this chain wheel l2 a frictionlining I3 is fixed. The bobbin l I has also a friction lining l5 and canrotate freely on bolt Hi. This bobbin is pressed by a spring I! and aplate [8 axially to the chain wheel l2, so that the bobbin II is rotatedby the friction linings l3 and IS. The force turning the bobbin H keepsthe pair of binding threads 5 in tension and winds them onto the bobbin.

Fig. 2 shows a side view of the knife 6 which cuts the weft threads. Thecutting edge 2| of the knife is preferably arranged obliquely to theplane of the fabric I. The knife 6 is screwed to an angle-iron extensionpiece 1 on the lever 1. In Fig, 3 an example of a fabric made on amultiple-box loom is shown, in which the outermost binding threadschange their shed when the shuttle is at the other side of the fabric.The weft threads 25 connected to each shuttle in the change boxes notshown in the drawings, are connected together by the outermost pairs ofbinding threads 26 at some distance from the edge of the fabric 24.These binding threads 26 are in accordance with the invention 'zept intension and the weft threads projecting from the fabric are severedclose to the fabric 24 by the knife 21. Along with the binding threads26 the severed ends 25 are drawn away and rolled up on a bobbin II asshown in Fig. 1. Since all severed weft threads ends are thus removedfrom the machine, no suction apparatus or the like is required for theirremoval.

Fig. 4 also shows another example of a fabric made on a multiple-boxloom and trimmed according to the invention. In this case, however,

the outermost pair of binding threads 32 changes shed at each pick, sothat not only the weft threads connected to the shuttles in thechangebox, but all the weft threads are connected together. In this caseit will be preferable to provide a second pair of binding threads 34,closer to the fabric, in order to make a proper edge to the fabric. Theweft threads 30 are cut by the knife 33, and the connecting threads 32are kept in tension by a tensioning device not shown in the figure.

With the present invention it is possible, with very simple means andvery neatly, to cut the weft threads projecting from the fabric. Thiscutting can be don directly on the loom, thus making it unnecessary topass the woven material through a special expensive shearing machine.

I claim:

1. In a loom for weaving, a mechanism for cutting the weft threadsextending in a fabric between two pairs of warp threads, said mechanismcomprising a knife blade positioned at a substantially right angle tothe plane of the fabric and having a substantially straight cutting edgein inclined position with respect to the fabric and extending throughand severing the weft threads between the pairs of warp threads when thefabric is moved in the direction running up said inclined edge, and asupport member mounted on the loom swingably about an axis substantiallyat right angle to the fabric, said knife blade being connected with andsupported by said support member,

2. In a loom for weaving, a mechanism for cutting the weft threads in afabric between two warp threads, said mechanism comprising a knifeholder mounted on the loom swingably about an axis substantially at aright angle to the fabric, a knife blade connected with said holder andbeing positioned at a substantially right angle to the fabric and havinga cutting edge in inclined position with respect to the plane of thefabric and extending through and severing the weft threads between saidwarp threads when the fabric is moved in a direction running up saidinclined edge, and actuating means connected with said holder and movingsaid holder so that said blade is pressed toward one of said warpthreads.

3. In a loom for weaving, a mechanism for cutting weft threads extendingfrom the woven fabric between the outermost warp threads and the nextinner warp thread, said mechanism comprising a knife blade disposedlaterally movably and at a substantially right angle to the plane of thefabric and having a cutting edge in inclined position with respect tothe fabric and extending therethrough and severing the weft threadsbetween said outermost warp threads and the next inner warp thread, andtensioning means maintaining tension on said outermost warp threads.

4. In a loom for weaving, a mechanism for cut-- ting weft threadsbetween an outermost warp thread and an inner warp thread, saidmechanism comprising a knife blade disposed at a substantially rightangle to said weft threads and extending therethrough and severing theweft threads between said outermost warp thread and said inner Warpthread, tensioning means maintaining tension on said outermost warpthread, and a knife holder connected with said blade and mounted on theloom swingably about a fulcrum disposed substantially at a right angleto said warp and weft threads and affording a laterally swinging motionof said blade between the outermost warp thread and the inner warpthread.

5. In a loom for weaving, comprising a mechanism as set forth in claim 4and having resilient means connected with said holder resilientlypressing said blade toward said inner warp thread.

6. In a loom for weaving, a mechanism for cutting the weft threadsextending in a fabric between two pairs of warp threads, said mechanismcomprising a knife blade holder mounted on the loom swingably about anaxis substantially at right angles to the fabric, a knife blade rigidlyconnected with said holder and being positioned at a substantially rightangle to the fabric and having a cutting edge in inclined position withrespect to the plane of the fabric and extending through and severingthe weft threads between said pairs of warp threads when the fabric ismoved in the direction running up said inclined edge, said knife bladebeing relatively thick and said edge extending between the planes inwhich the sides of said blade are located whereby the warp threadsadjacent to the blade are held at a distance from the cutting edge andprotected against being cut.

7. The method of cutting off the weft thread ends projecting from thefabric while it is still on the loom on which it has been woven,comprising the steps of tensioning the outermost warp threads separatelyfrom and independently of the fabric after they have been woven-in inspaced relation from the remainder of the warps, and of cutting the weftthreads adjacent to the inside of the separately tensioned warp threads.

8. The method of cutting the weft thread ends projecting from the fabricwhile it is still on the loom on which it has been woven, comprising thesteps of applying tension to the outermost warp threads substantially inthe direction of the movement of the fabric and after they have beenwoven-in in spaced relation from the remainder of the warps, and ofcutting the weft threads inside of said tensioned outermost warp threadsand at a point separated from the last beaten up weft thread by aplurality of woven in weft threads.

9. The method of cutting off the weft thread ends projecting from thefabric while it is still on the loom on which it has been woven,comprising the steps of tensioning the outermost warp threads separatelyfrom and independently of the fabric after they have been Woven-in inspaced relation from the remainder of the warps, of cutting the weftthreads between the tensioned warp threads and a warp thread which isinside of said separately tensioned warp threads, and of drawing saidoutermost warp threads away from the fabric.

10. The method of cutting off the weft thread ends projecting from thefabric while it is still on the loom on which it has been woven,comprising the steps of tensioning the outermost warp threads, afterthey have been woven-in in spaced relation from the remainder of thewarps, separately from and independently of the fabric and substantiallyin the direction of the movement of the fabric, of cutting the weftthreads between the tensioned warp threads and a warp thread which isinside of said separately tensioned warp threads, and of drawing saidoutermost warp threads away from the fabric after the weft threadsconnecting said warp threads with the fabric have been cut.

ALBERT MOESSINGER.

